Eight Root Causes of Flaky Playwright Tests and How to Fix Them

Flaky tests — those that pass and fail inconsistently without any code change — are not random but stem from deterministic, unaddressed triggers such as timing issues, shared state, and unmocked external APIs. A technical deep-dive on DEV Community identifies eight core root causes behind this non-determinism in Playwright test suites. The piece explains that Playwright's built-in auto-waiting cannot account for app-specific behaviors like debounce delays or animation transitions, requiring developers to write explicit, state-aware assertions. Shared browser context between tests, including leftover cookies or database rows, is highlighted as one of the most underestimated sources of flakiness, particularly when tests run in parallel. The article provides practical code fixes for each cause, arguing that relying on retries merely papers over the problem rather than restoring genuine trust in automated test pipelines.